Field of the Invention
The present invention relates to an audio output system utilizing a speaker and adapted to transmit audio relating to an image displayed on a screen toward a direction opposed thereto, and a method therefor.
There are currently commercialized several speaker systems capable of reproducing realistic sound. Among these, there is known a surround system utilizing the DVD (digital video disk) as the sound source and the image source. Such DVD system, utilizing the digital Dolby recording, can realize realistic sound by executing the reproduction by the digital Dolby system.
This system however requires five speakers, namely under the image display, behind the listener, for very low sound, left and right.
On the other hand, in a television (TV) conference system employing personal computers and television sets, while the image of a speaking person is displayed on the screen 101a as shown in FIG. 9, the voice of such person is normally outputted from speakers 102a, 103a positioned on both lateral sides of the screen. FIG. 9 is a plan view of a conventional TV conference system.
Also in case the voice of the speaking person has to be heard only by the listener 104a or in case the sound output is molesting to other persons, the sound has to be heard with the headphones or earphones.
On the other hand, there are recently increasing occasions of presentations of new business plans or the like with personal computers. In such occasion, a larger screen is preferred in order to give a strong impression to the viewers.
Also in case of viewing television or video at home, a larger screen is preferred for increasing the impact or the feeling of reality.
Furthermore, it is quite common to display the image video of a company or the commercial film of new products on a large screen at various exhibitions or shows in order to advertise the value of such company or products. Such larger screen used at the exhibitions or shows is often constituted by combining several large-sized television sets. Also a plasma display or a rear projector is increasingly used for this purpose.
In such case it is important to design the sound effect in combination with the image displayed in the screen, because the effect of the image can become good or bad, depending on the sound effect.
Usually well known is the stereo sound effect utilizing speakers positioned at left and right of the large screen. Also there is employed the surround sound effect for increasing the appeal to the listener by providing sound from the front, rear and lateral sides.
However the sound reproduction by the aforementioned digital Dolby system not only involves a higher cost for the necessary equipment but also a large space for installing the speakers.
Also in the TV conference system explained before, the voice of the speaking person, released from the speakers at right and left of the screen, does not sound as if spoken by the person displayed on the screen, thus lacking the feeling of reality.
Also as a drawback common to the foregoing two systems, the output sound can be heard by a person irrelevant from such sound and may give unpleasant feeling thereto.
On the other hand, in order to shield irrelevant persons from the output sound, it is necessary to use headphones or the like, so that the convenience of use becomes deteriorated.
Furthermore, there are required considerable spaces in order to place the speakers at right and left of the screen. Also, in order to realize the surround sound effect, it is necessary to install the speaker behind the listener in addition to the front side. Consequently there is required an even larger space, and the number of the listeners is inevitably limited, rather contrary to the objective to give presentation to as many persons as possible. Furthermore, the installation of the speakers requires complex wirings, involving a larger amount of work and possibility of erroneous wirings.
In consideration of the foregoing, an object of the present invention is to provide an improved audio output apparatus or system capable of solving all or at least one of the aforementioned drawbacks.
Another object of the present invention is to provide a novel audio output method utilizing such apparatus, system or method.
Still another object of the present invention is to provide audio output apparatus, system and method capable of realizing, with a limited number of speakers, a real effect as if the speaking person displayed on the screen is really speaking.
Still another object of the present invention is to provide audio output apparatus, system and method capable of rendering the sound outputted from the speaker less audible to the irrelevant persons thereby making the sound less annoying thereto.
Still another object of the present invention is to provide audio output apparatus, system and method allowing the listener to experience the surround sound effect by a highly directional speaker mounted on a projector used for projecting the image.
The above-mentioned objects can be attained, according to an embodiment of the present invention, by an audio output apparatus for transmitting the sound, relating to the image displayed on the screen, toward a side opposed thereto, the system comprising an image display unit having a screen for displaying the image, a reflective member provided on the screen of the image display unit and adapted to reflect the sound wave, and a speaker for generating a sound wave corresponding to the sound, wherein the speaker is so positioned that the sound wave generated by the speaker is reflected by the reflective member and is emitted toward the side opposed to the screen of the image display unit.